1. Field of the Invention
The present invention relates to a process for silvering articles, particularly textile articles, in order to make them conductors of electricity and improve their antistatic properties.
More particularly it applies to yarns intended for the manufacture of floor coverings such as carpets or rugs, wall coverings, and articles of clothing.
As a matter of fact, these articles, if they do not have good antistatic properties, will very rapidly become dirty due to the attraction of dust suspended in the air which has become electrically charged by friction. It is very difficult to keep these articles clean since the dirt, which remains on their surface, is difficult to eliminate. Another drawback resides in the fact that the user, upon coming into contact with a surface which is not antistatic, frequently receives discharges due to the accumulation of static electricity. Thus for reasons of safety, it is necessary to provide articles having antistatic properties. In addition to the above interest due to these properties, the articles obtained in accordance with the invention may also be used, due to their good conductivity, in the specialized field for the manufacture of heating articles such as floor covering, heat coiling, heating garments, etc.
2. Description of the Prior Art
One method of metallization which has been known for a long time consists of treating the articles with a solution of a metal salt and then reducing the metal salt to the metallic state by treatment with a reducing agent. However, the deposit of metal has the drawback that it adheres poorly to the treated article. Various solutions have been proposed in order to overcome this drawback. For example, as described in U.S. Pat. No. 3,058,845, it is possible to add swelling agents to the metallic salt treatment bath or else to carry out a preliminary treatment in accordance with French Patent Application No. 2,002,131 in order to sensitize the surface of the article to be treated. Another well known process as described in U.S. Pat. Nos. 2,303,871 and 2,355,933 and French Applications Nos. 2,002,131 and 2,108,024, consists in pretreating the article with a reducing agent and then treating it with a solution of the metal salt. However, in order for these treatments to give good results, it is necessary to add another reducing agent to the metal salt solution or to carry out a pretreatment to activate the surface to be treated.
All of these methods are complicated, since they involve either two treatment steps with baths containing different products, or at least three treatment steps with an additional activating step. Moreover, the adherence of the metal to the treated article is not always satisfactory.